Prob9_PointsInsideTheHouse

import java.util.Scanner;

public class Prob9_PointsInsideTheHouse {
    public static void main(String[] args) {
        Scanner input = new Scanner(System.in);

        System.out.print("Please enter the coordinates of the point in question: ");
        Point givenPoint = new Point(input.nextDouble(), input.nextDouble());
        Point[] leftRec = new Point[]{new Point(12.5, 8.5),new Point(12.5, 13.5),
                new Point(17.5, 13.5), new Point(17.5, 8.5)};
        Point[] rigthRec = new Point[]{new Point(20, 8.5),new Point(20, 13.5),
                new Point(22.5, 13.5), new Point(22.5, 8.5)};
        Point[] triangle = new Point[]{new Point(12.5, 8.5),new Point(22.5, 8.5),
                new Point(17.5, 3.5)};
        boolean isInside = Point.isInsideFig(leftRec,givenPoint) || Point.isInsideFig(rigthRec,givenPoint) ||
                 Point.isInsideFig(triangle,givenPoint);

        if (isInside){
            System.out.println("Inside");
        } else {
            System.out.println("Outside");
        }
    }
}

class Point{
    private double x;
    private double y;

    public Point(double x, double y){
        this.x = x;
        this.y = y;
    }

    public double getX(){
        return this.x;
    }

    public void setX(double x){
        this.x = x;
    }

    public double getY(){
        return this.y;
    }

    public void setY(double y){
        this.y = y;
    }

    public static boolean isInsideFig(Point[] fig, Point pointInQ){
        boolean isIn = true;

        for (int i = 0; i < fig.length; i++) {
            int index = i+1;
            if (i == fig.length-1) {
                index =0;
            }
            double findSign = (fig[index].x - fig[i].x)*(pointInQ.y - fig[i].y) -
                    (fig[index].y - fig[i].y)*(pointInQ.x - fig[i].x);
            if (findSign > 0) {
                isIn = false;
            }
        }
        return isIn;
    }
}